Answer:
A thermistor is a type of resistor whose resistance varies significantly with temperature. The main function of a thermistor is to measure temperature or to compensate for temperature variations in a circuit. Here are some key points about thermistors:
Temperature sensitivity: Thermistors are highly sensitive to temperature changes, making them suitable for precise temperature measurements.
Resistance-temperature relationship: Most thermistors have a negative temperature coefficient (NTC), meaning their resistance decreases as temperature increases. Some thermistors have a positive temperature coefficient (PTC), with resistance increasing with temperature.
Applications in temperature measurement: Thermistors are used in various temperature sensing applications, such as in thermostats, temperature probes, and digital thermometers.
Temperature compensation: Thermistors can be used to compensate for temperature-induced changes in electronic circuits, ensuring stable performance over a range of temperatures.
Circuit protection: PTC thermistors can be used as resettable fuses to protect circuits from overcurrent conditions. As current increases, the thermistor heats up and its resistance increases, limiting the current flow.
Small size and low cost: Thermistors are generally small, inexpensive, and easy to integrate into electronic circuits.
In summary, the primary function of a thermistor is to provide a temperature-dependent resistance that can be used for temperature sensing, compensation, and protection in various electronic applications.